CVE-2026-8948
Critical
Description
Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
SeverityCritical
CVSS9.1
Exploit probability—
Product
Mozilla Firefox
PublishedMay 19, 2026
First seenMay 19, 2026
Weakness typeCWE-942CWE-942CWE-79Cross-site scripting (XSS)
How to fix
Update
- mozilla firefox151.0.0 or later
- mozilla thunderbird151.0.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mozilla firefox | v < 151.0.0 | 151.0.0 |
| mozilla thunderbird | v < 151.0.0 | 151.0.0 |
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